The present invention relates to surgical retractors and devices for stabilizing a predetermined area of the body during a surgical procedure, more particularly to surgical retractors and stabilizing devices used in connection with minimally invasive coronary artery bypass grafting surgical procedures, and more specifically to surgical retractors and stabilizing devices especially configured for use with each other for such surgical procedures.
Diseases of the cardiovascular system affect millions of people each year and are a cause of death for large numbers of people in the United States and throughout the world.
A particularly prevalent form of cardiovascular disease involves a reduction in the blood supply to the heart caused by atherosclerosis (coronary artery disease) or other conditions that create a restriction in blood flow at a critical point in the cardiovascular system leading to the heart.
One technique for treating such a blockage or restriction is a surgical procedure known as a coronary artery bypass graft procedure, which is more commonly known as xe2x80x9ca heart bypassxe2x80x9d operation. The surgical correction of occluded or stenosed coronary arteries by means of bypass grafting are probably still the most common procedures performed today, especially when multiple grafts are needed.
In the coronary artery bypass graft procedure, the surgeon either removes a portion of a vein from another part of the body for grafting or detaches one end of an artery and connects that end past the obstruction while leaving the other end attached to the arterial supply. When using a vein from another part of the body, the surgeon installs this portion at points that bypass the obstruction. In both cases, the objective is to restore normal blood flow to the heart.
In addition, when using this technique the surgeon makes a long incision down the middle of the chest, saws through the sternum, spreads the two halves of the sternum apart and then performs several procedures necessary to connect the surgical patient to a cardiopulmonary bypass machine to continue the circulation of oxygenated blood to the rest of the body while the heart is stopped and the graft is being sewn in place although such a procedure is one common technique for treatment, the procedure is lengthy, traumatic, considerably expensive and can damage the heart, the central nervous system and the blood supply.
Interventional techniques, such as percutaneous transluminal angioplasty (PTCA) have gained popularity as the method of choice for therapy of atherosclerosis occlusions for several reasons. The transluminal approach is a minimally invasive technique that subjects the patient to less trauma and less recovery time, especially when compared to bypass grafts which utilize homologous tissue, such as saphenous vein grafts. Also, the patient often suffers complications at the donor site of the graft that may be worse than the sternotomy and anastomosis.
Although PTCA procedures are often successful, complications such as restenosis or thrombosis and embolism can occur. Restenosed vessels may often require surgical intervention for correction. The surgical correction of restenosis like the conventional coronary bypass surgical procedure requires the heart to be stopped and the patient placed on a heart/lung bypass machine during the procedure.
In recent years, and in an effort to reduce expense, risk and trauma to the patient, physicians have turned to minimally invasive surgical approaches to the heart, such as intercostal and endoscopic access to the surgical site. With such procedures, the heart is beating during the surgical procedure. Thus, there is no need for any form of cardiopulmonary bypass and there is no need to perform the extensive surgical procedures necessary to connect the patient to such a bypass machine.
Such attempts at performing minimally invasive bypass grafting on a beating heart, however, have been thought of as being tedious, dangerous and difficult because of the delicate nature of the surgical procedure, the lack of adequate access through a reduced surgical field, and the lack of a way to adequately stabilize and reduce tissue movement at the graft site. Because these procedures are performed while the heart muscle is continuing to beat, the blood continues to flow and the heart continues to move in three dimensional movement while the surgeon is attempting to sew the graft in place. Also, the surgical procedure to install the graft requires placing a series of sutures through an extremely small vessel and onto tissue that continues to move during the procedure. It is necessary that these sutures be fully and securely placed so the graft is firmly in position and does not leak.
There is disclosed in U.S. Pat. No. 5,730,757, an access platform for the dissection of an internal mammary artery. The described access platform has first and second blades interconnected to a spreader member that laterally drives the blades apart together and support pads interconnected to the first blade. A torsional member is operably interconnected to the first blade and the spreader member and is used to vertically displace the first blade in either direction. Thus, increasing the surgeon""s working space and visual access for the dissection of the internal mammary artery. A tissue retractor interconnected to the blades is used to draw the soft tissue around the incision away from the surgeon""s work area. It is further provided that the access platform can include a port that can be used to mount a heart stabilizer instrument.
There also is described in U.S. Pat. No. 5,875,782 granted to Ferrari et al. and U.S. Pat. No. 5,894,843 granted to Benetti et al. an apparatus for stabilizing the predetermined area on a heart or other organ of a patient to enable a surgical procedure on a beating heart. The apparatus includes a bifurcated member having two elongated prongs and an elongated handle. The handle segment can be movably attached to a rib retractor so that a person is not required to hold the handle segment. In one disclosed embodiment, the apparatus further includes a device to hold the bifurcated member in a position against the surface of the heart sufficiently so that a stabilizing force is applied against the heart and contraction of the heart does not cause either vertical or horizontal motion at the target site during the surgical procedure.
There also is described in U.S. Pat. No. 5,836,311 granted to Borst et al. an apparatus for stabilizing the predetermined area on a heart or other organ of a patient to enable a surgical procedure on a beating heart. The apparatus includes a single legged or bifurcated member having a plurality of suction members thereon which are attached to the surface of the heart using suction pressure. The arm portion of this device can be movably attached to a rib retractor or other surgical device so a person is not required to hold the handle segment and the suction device may be locked into position against the surface of the heart
It is therefore desirable to provide a new system and devices related thereto for stabilizing a predetermined area of the body, such as the heart and methods related thereto. It is particularly desirable to provide such a system and devices thereto that are less complex and more user friendly in comparison to prior art devices. Such systems and devices thereto preferably are simple in constriction and less costly than prior art devices.
The present invention features a system for retracting, stabilizing or manipulating a predetermined area of a body. The system includes a surgical retractor, a stabilization arm or apparatus and a tissue support or stabilization device, and methods of use related thereto. Also featured is a system that supports any of a number of surgical implements, for example a diaphragm retractor, a valve retractor, a light or suction device for use during a surgical procedure. The stabilization system and related devices and apparatuses thereto that are featured herein are particularly advantageous for use in performing off-pump coronary artery bypass grafting procedures in which the heart remains beating during the surgical procedure. One advantage of the present invention relates to the use of the external rail system on the arms of the retractor and even more preferably also on the rack segment of the retractor. The use of the external rail systems allows the stabilization arm to be attached to the retractor at any desired location and does not require that the stabilization arm be slid on from an end of an arm or specially attached in certain specific locations. Additionally, the sled of the present invention allows for a full range of motion which is controlled by a single knob that is easily manipulated by the surgeon.
In a general aspect, the stabilization system of the present invention is preferably used for stabilizing a predetermined area of a patient. This system preferably includes a retractor, a stabilization device for locally stabilizing the predetermined area and a stabilization arm that functionally secures the stabilization device to the retractor. The retractor preferably includes a rail system having two arms and a rack segment. The rack segment interconnects the two arms, for selectively spacing the two arms from each other and for maintaining the two arms in a desired fixed relationship. In a preferred form of the present invention, the two arms and rack segment are configured to receive the connector of the stabilization arm at the desired location thereon.
The stabilization device preferably includes a device of the type commonly known as the Cohn Cardiac Stabilizer marketed by the Genzyme Corporation of Cambridge Mass., although horseshoe or suction type devices may also be used. The preferred form of the stabilization device is a generally square or rectangularly shaped member having a planar surface with centrally located opening therein. This opening is the area through which the surgeon performs the anastomosis or other procedure on the tissue of the beating heart. The stabilization device is preferably a two piece member so that once the anastomosis is completed, the pieces may be separated to remove the device from around the anastomosis. As described more fully below, flexible tapes are sutured through the tissue and then threaded through the stabilizing device. Once the stabilization device is positioned in the desired orientation and location in contact with the tissue, the flexible tapes are then pulled snug through the opening of the stabilization device to provide a system which minimizes the overall movement of the predetermined area of the tissue.
The stabilization arm preferably includes an elongated handle having a first end and a connector thereon for releasably connecting the stabilization device to the elongated handle first end. This connection allows the stabilization device to be pivotally and slidably moved to a desired position into contact with the predetermined area of the tissue of the patient. The stabilization arm also includes a mounting mechanism or sled member which is preferably slidable along the handle segment for removably securing the stabilization arm to at least one of the rails on the retractor arms and/or the rack segment of the retractor.
According to one aspect of the present invention, the arms of the retractor arc configured with a front edge and a step in the top surface thereof to form an elongated rail surface along substantially the entire length thereof. The step is preferably spaced apart a predetermined and consistent distance from the front edge and is also located on the interconnecting or rack segment of the retractor. Also, the stabilization arm preferably includes a mounting mechanism or sled member which is configured to removably engage the front edge and the step at any desired location on one or more of the arms or the rack segment of the retractor. The mounting mechanism includes a lever for selectively engaging the step and front edge on the arm or rack segment of the retractor so the mounting mechanism is removably and slidably secured to the arms or the rack segment.
In another aspect of the present invention, there is featured a surgical retractor including two arms, a rack segment and a plurality of sternal blades with at least one blade extending downwardly from each arm. Each blade includes an upper section adjacent to the bottom surface of the arm and a lower section extending distally of the arm. A slot on the bottom surface of the arms includes a tapered surface adjacent to the front edge thereof to facilitate the placement of the blades on the arms. A lip surface is also located adjacent to the slots on the bottom surface of the arms to securely retain the blades on the bottom surface of the arms during the procedure while still allowing the blades to be easily removable for initial positioning and subsequent sterilization following the procedure.
In yet another aspect of the present invention there is featured a sled member or mounting mechanism that allows the user to retain the stabilization arm in a sliding and fixed relationship relative to the retractor and patient while also allowing for the rotation of the sled member with respect to the retractor by manipulating a single knob. Furthermore, a lever on a bottom section of the sled member allows the sled member to be slidably and fixedly positioned along the arms and rack segment of the retractor. Each of these features enables the user to determine the optimum position for the stabilization arm and stabilization device while ensuring that the surgeon""s view of the operative area is not unnecessarily obstructed. Additionally, these features allow the present invention to be used in many different medical procedures because of the versatility of system set up and orientation of the components of this invention.
Other aspects and embodiments of the invention are more fully discussed below.